Convertible magneto



Jan. 22, 1935. LE RQY 5, DUNHAM ET AL 1,988,724

CONVERTIBLE MAGNETO Jam 22, l935- LE RoY s. pUNHAM Er AL 1,988,724

CONVERT I BLE MAGNETO Jan. 22, 1935. LE ROY s. DUNHAM Er AL 1,988,724

CONVERTIBLE MGNETO Filed May 12, 1935 4 Sheets-Sheet 3 ATTORNEY Jan- 22, 1935- LE ROY s. DUNHAM Er AL 1,988,724

C ONVERT I BLE MAGNET() Filed May l2, 1955 4 Sheets-Sheet 4 Patented Jan.v 22, 1935 UNITED STATES PATENT OFFICE CONVERTIBLE MAGNET() Le Roy S. Dunham, East Orange, and Arthur F.

Robertson, Belleville, N. J., assignors to Edison- Spltdorf Corporation, West Orange, N. J., a corporation of New Jersey Application May l2, 1933, Serial No. 670,654

14 Claims. (Cl. 123-149) This invention relates to a special design of of Figure 7, showing the advance lever and timer electric generator of the magneto type, espeplates. l cially adapted for use in igniting charges in Figure 9 is a plan-view of the fixed timer internal combustion engines. plate. 5 It is the principal object oi' our invention to Figure 10 is a plan-view of the. movable timer 5 provide a magneto in which the main frame plate which is associatedwith the plate shown I structure can be utilized in a considerable numin Figure 9.

ber of machines suitable for different ignition Figure 1l is a vertical, sectional, elevational purposes. view on the line 11-11 of Figure 12, through a l It is another object of our invention to profour-cylinder style of magneto using our unitary l0 vide a single unitary frame structure which, frame structure. while attaining the main object as expressed Figure 12 is an end-view of Figure 1l. above, at the -same time reduces the cost of Figure 13 shows a further modified form o! manufacture, as the number of parts required magneto on the line 13-13 of Figure 14, showing l to build the various combinations, which will be a type of distributor such as used on battery 15 hereinafter set forth, is reduced to a minimum. ignition installations. This improved design allows the main magneto Figure 14 is a part-sectional view and partstructure to be convertible into any one of a elevational view on the line 14-14 of Figure 13. number of different styles of magnetos suitable Referring now to the details, lwherein like for various purposes, from a one-cylinder engine numbers refer to corresponding parts in the 20 to any of the usual number of multi-cylinder various views, 1 is a frame structure having a engines. plurality of mounting bosses 2. The frame The various styles of magnetos which may be structure carries a core 3 for an ignition coil 4. developed from the fundamental frame struc- The core 3 is made up in the usual manner of a ture will be more specifically hereinafter set plurality of laminations of good magnetic ma- 25 forth. terial. As shown in Figure 2, the lower end of Our invention will be understood by reference the core is provided with horns or projections to the annexed drawings, wherein: l 5 which are interlocked in the die-casting proc- Figure l is a longitudinal view through on ess with the frame structure 1. By utilizing the style of magneto, a single-cylinder fixed spark construction as indicated, a very secure mount- 30 machine being illustrated. ing for the core 3 is obtained whereby the ma- Figure 2 is a section on the line 2-2 of Figure chining operations across the top of the core l, but with the ignition coil omitted, the conwill not loosen it or disturb its mounting in the denser shown in dotted position, and the rotor/ frame.

at the point where the spark is produced, the The frame 1 also carries a group of lamina- 35 direction of rotation being indicatedy by the tions comprising a keeper 6, the upper end of arrow. which terminates in a line parallel with the free Figure 3 is a fragmentary plan-view of a porend of the core 3. The frame structure 1 tion of the upper part of the magneto frame also carries a pole-shoe 'l which preferably 40 structure with the removable top taken off. has a. seat 8 for a magnet 9, the magnet being 40 Figure 4 is a cross-sectional view on the line held in position in the frame by screw 10. 'Ihe 4-4 oi Figure 5. but showing a higher top for frame 1 has integral end members 11 and 12 the frame than that shown in Figure 1. between which is positioned a rotor shaft 13 Figure 5 iS a plan-View 0f the under Side 0f preferably carried on anti-friction bearings 14 either the 10W top Shown in Figure 1, 0r the and 15. The shaft 13 carries an inductor 16 45 high top of Figure 4. which serves to vary the flux through the core Figure 6 ShOWS 2. Sectional View 0n the lille 3 and hence through the coil 4, Adjacent the 6-6 0f Figure 7, through the breaker end 0f coil 4 is a condenser 17 shown in dotted lines in the magneto of a two-cylinder manual advance Figures 1 and 2, The end-member 11 gf the typeframe also carries an insulator 18 which sup- 50 Figure 7 iS e pluri-View 0f Figure 6 ShOWng ports a high-tension terminal 19, a cable 20 bethe method of fastening the advance lever arm ing indicated as running from the terminal 19 and the circuit breaker guide pin, and also showto the coil 4. ing the ends of the timer plates. The unitary frame structure so far described,

Figure 8 is a fragmentary side-view of part can be built up or converted into a number of 55 nu i' various -types of magnetos which will now be described.

For certain types, the frame structure is providedwith a top as shown in Figure 1, which comprises a box-type frame 21 composed of nonmagnetic material preferably similar to the frame 1, and in this box 21 there is mounted, as more particularly shown in'Figure 5, a group of laminations 22 which comprises a yoke extending across the outer ends of the core 3 and the keeper 6, and to a point where the ends thereof are engaged by the magnet at the point 23.l

The laminations 22 are riveted together by= pins 24 which extend-into the wedge-shaped pieces 25` and 26, and they may also extend, as shown in Figure 5, into the box-frame 21, thereby locking the laminations 22 securely in position inv the top of the magneto. This top is held to the frame structure in any satisfactory manner as by screws entering screw-holes, two of which .are shown at 27 in Figure 3.

As shown in Figure 1, the end-member 12 is itted with a breaker-box 28, being held thereto in any satisfactory manner as by a plurality of screws 29. The breaker-box 28 carries a stud 30v on which is mounted the arm oi a movable circuit breaker which is operated by a cam 31 fastened to the shaft 13'by a screw 32. The breaker-box 28 is provided with a cover 33 held in position by springs 34. Thus is provided, as shown in Figure l, a single cylinder fixed spark magneto, and in such type magneto it is sometimes desirable to use a grounding switch as indicated'by the push-button 35 shown in dotted line, which is adapted to engage contact spring 36 connected to a grounding stud 37 to which one end of the primary of the coil 4 is connected. While the condenser 17 is shown within the frame structure l, it may in some cases be carried in the combination bearing and circuitbreaker housing.

y In Figure 4, the construction of the cover is similar to that just described withA respect to Figure 1, except that it is deeper, including of course the laminations 22. Using this deeper cover, provides a greater space for the coil 4 and a larger coil may be used, together with a longer magnet 9. 'Ihese conversions produce a magneto like Figure 1, but having a `greater output which is sometimes desirable, depending on the size of -the engine to which' the magneto is applied.

Suppose now it is desired to have a variable spark with this single-cylinder magneto that has been described in' Figure 1. To obtain this, the style of bearing' and breaker-box housing 28, shown in Figure 1, is removed, and a bearing rations 42 as on the plate 41, and aslot 45 positioned over the slot 43. The timer plate 44 is provided with a pair of end-slots 46 in which are positioned the screws'47 which pass through the slots 46 into the holes 40 in the frame of the magneto.

This construction just described gives an adjustment for the plate 44 whereby the position of the slot 45 may be varied, and consequently the throw of the advance lever 48 is`changed according to the position of the plate v44 with respect to the plate 41. This enables the circuit breaker to be properly timed with respect to the break of` the inductor 16 from the pole-tip 49, whereby the spark will be produced at the proper timewith respectto the,z maximum change of` the flux through thecoil-core 3. It may be mentioned that the advance lever 48 is fastened to a cup-shaped breaker plate 50 which rotatably (fits within the breaker-box 51, it being understood that the circuit breaker parts and cam are the same as have been described with respect to Figure 1. The lever 48 may be mounted on 'either side of the circuit breaker housing, and when mounted, as for' examplein Figure 7, the slot in the breaker housing n the opposite side is covered by a plain-plate 72. The bosses 2 have been provided to give a standard S. A. E. height for the shaft 13, but if a shorter dimensionis required between the mounting plate `and the shaft center, the bosses 2 may be machined down to give the desired height.

Suppose now it is desired to have a two-cylinder magneto ywith a xed spark, with a relatively low output. We would then use the frame structure and top of Figure 1 with the breakerbox 28, but the cover 33 is removed and a distributor cap 52, -of good insulating material, such as shown in Figures 6 and 7, is mounted in its place, being held in position by the same springs`34. It will be noted from Figure 6, that for a two-cylinder magneto, a different cam must be used, and this cam is slotted at 53 to receive a distributing nger 54. 'Ihe finger 54 carries a flexible contact spring 55 adapted to make contact with the terminal 56. The distributing finger 54 also carries a distributor contact member 57 which will distribute the sparks to the terminals 58 and 59 inthe usual manner for a jump spark machine. It is to be understood that the high-tension terminal 19 (see Figure 1) is connected by a flexible cable around the side oi the magnetov to the terminal 56, whereby the sparking current is then distributed as has been described.

If a larger output is desired for this style of der variable spark machine, then the type of breaker-box 51 as shown in Figures 6, 7, and 8, is ,utilized in the same manner as has been described for thesingle-cylinder magneto.

From what has been said, it will be seen that we can obtain, from the structures so far described, eight combinations, all utilizing the same frame structure including the same rotor.

If a four-cylinder magneto is desired, as illustrated in Figures l1 and l2, an additional housing member 60 is required for supporting a distributor gear 61 whichis driven by a pinion 62 carried on the rotor shaft 13. The distributor gear 61 is supported on a bearing collaror member 63, on the outer. end of which is affitting 64 formed to carry the same distributor finger 54 as shown in Figure 6. The frame member 60 also carries a four-cylinder distributor block 65 and a circuit breaker which may be similar to that shown in the previous figures. However, the circuit breaker-,that is shown is that described in our Patent 1,887,624, issued November 15, 1932. Therefore, the various parts need not be specifically described herein.

In this type of magneto, the frame structure remains the same and may use either the high or the low top with thev corresponding magnet as has been described, but the rotor shaft is somewhat longer in order to carry the pinion 62 and the circuit breaker parts. It may also be mentioned that the teminal 19 (see Figure 1) is connected to the central terminal 66 by a flexible cable in the same manner as has been dev scribed with respectvto the connection to the terminal 56 of Figure 6.

In Figures 13 and 14, we have shown a distributor, generally referred to by thenumber 67, of the battery ignition type, the drive for the distributor shaft 68 being made through a gear 69 and pinion 'I0 carried on the end of the rotor shaft 13. In this arrangement, the rotor shaft 13, at the gear end 70, is of a different length than that shown in Figure 11, but in all forms of the magneto, the drive-end of the rotor shaft is the same standard S. A. E. type. It is also to be noted that in the form shown in Figures 13 and 14, the same distributor finger 54 is utilized as in all the previous forms, and likewise, the same cup-shaped breaker-plate 50, as shown in Figure 6. r In this form, the cable from the high-tension lead 19 is connected to the central terminal 71 in a similar manner as has been described with respect to the other forms. In this type of magneto, the high or low top for the frame structure may be utilized, thus giving, as so far Idescribed, two types of magnetos of the form shown in Figures 11 and 12, and two types of the form shown in Figures 13 and 14.

A similar construction is. followed out for six or eight-cylinder machines as has been described with respect to the four-cylinder arrangements.

From what has been said, it will be understood that many of the details utilized in this convertible magneto structure may be varied over a considerable range, without -departing from the spirit of our invention and the scope of the appended claims.

Having thus described our invention, what we claim is:

l. In a convertible magneto having a rotor, the combination with a unitary frame structure, including a housing for the rotor and its field poles and an ignition coil with its associated core and field pole faces, said housing also directly carrying at the drive end, one of the rotor bearings; of a removable housing 28 at the breaker end, a rotor bearing and a circuit breaker carried by said housing, a cover for the housing and a removable top for the frame structure, said top carrying core parts to complete the magnetic circuits of the coil-core, and a magnet extending from the rotor pole in the frame structure, into engagement with the core parts in said ton.

2. In a magneto as set forth in claim 1, further characterized in that the characteristics of the magneto may be quickly changed by merely removing said top and replacing it with another having a different height, and replacing the magnet with one .suited to said new top.

3. In a magneto as set forth in claim 1, further characterized in that the characteristics of the magneto may be quickly changed from a single-spark fixed ignition to a single-spark adjustable ignition by changing said housing to one having a timing lever attached to the breaker' lplate in the housing and extending without the housing, said parts being quickly changeable for the reverse condition.

4. In a magneto as set forth in claim 1, further characterized in that the characteristics of the magneto may be quickly changed from a single-spark iixed ignition to a single-spark ad- Justable ignition by changing said housing to one having a timing lever attached to the breaker plate in the housing and extending without the housing, said parts being 'quickly changeable for the reverse condition, and further characterized in that the output characteristics of the magneto may be quickly changed by merely removing said top and replacing it with another having a different height, and replacing the magnet with one suited to said new top.

5. In a magneto as set forth in claim 1, further characterized in that the characteristics of the magneto may be,quickly changed from a single-spark fixed ignition to a two-spark fixed ignition by changing the circuit-breaker cam, mounting a distributor finger thereon, changing said cover to a two-spark distributor block and connecting the secondary terminal of the coil to said block, said parts being quickly changeable for the reverse condition.

6. In a magneto as set forth in claim 1, further characterized in that the characteristics of 2 the magneto may be quickly changed from a single-spark fixed ignition to a two-spark fixed ignition by changing the circuit-breaker cam, mounting a distributor finger thereon, changing said cover to a two-spark distributor block and connecting the secondary terminal of the coil to said block, said parts being quickly changeable for the reverse condition, and further characterized in that the output characteristics of the magneto may be quickly changed by merely removing said top and replacing it with another having a different height, and replacing the magnet with one suited to said new top.

'1. In a magneto as set forth in claim 1, further characterized in that the characteristics of the magneto may be quickly changed from a two-spark fixed ignition magneto to a twospark variable ignition by substituting for the housing 28,.the housing 51 and adjustable circuit breaker plate 50 with its associated parts, the remaining parts being those used in the twospark fixed ignition magneto, said housing 51 and plate 50 being quickly changeable for the reverse condition. y

8. In a magneto as set forth in claim 1, further characterized in that the characteristics of the magneto may be quickly changed from a two-spark fixed ignition magneto to a two-spark variable ignition\by substituting for the housing 28, the housing 51 and adjustable circuit breaker plate 50 with its associated parts, the remaining parts being those used in the two-spark fixed ignition magneto, said housing 51 and plate 50 being quickly changeable for the reverse condition, and further characterized in that the output characteristics of the magneto may be quickly changed by merely removing said top and replacing it with another having a different height, and replacing the magnet with one suited to said new top.

9. In a magneto as set forth in claim 1, further characterized in that the characteristics of the magneto may be readily made into a multicylinder machine by applying to the frame structure, an additional housing carrying all breaker and distributor parts for the desired number of cylinders, the described. l

10. In a magneto as set forth in claim lo further characterized in that the characteristics of the magneto may be readily made into a multicylinder machine by applying to the frame structure, an additional housing carrying all breaker and distributor parts for the desired number of cylinders, the rotor having a longer shaft as described, and further characterized in that the output characteristics of the magneto may be quickly changed by merely removing said top and replacing it with another having a different height, and replacing the magnet with. one suited to said new top.

11. In a magneto as set forth in claim 1, further characterized in that the characteristics of the magneto may be readily made into a multicylinder machine by applying to the frame struc ture, an additional housing carrying all breaker and distributor parts for the desired number of cylinders, the rotor having a longer Vshaft as described, and further characterized in that the Joutput characteristics of the magneto may be quickly changed'by merely removing said top and replacing it with another having a different height, and replacing the magnet with one suited to said new top, andstill further characterized in that the output characteristics may be still further changed lby changing the ignition coil.

12. A convertible magneto comprising a unitary frame structure including a housing carrying; a rotor, field core parts and an ignition coil fitting around but easily removable from rotor having a longer shaft as one of said core parts when the top of the magneto is removed, a top for said frame struc.

ture quickly removable therefrom for substitution of another, and all carrying core parts to complete the magnetic circuits through the magneto, a magnet mounted for quick removal for f substitution by another, and all extending from a rotor core part in the frame structure to the core part in the top as selected, and a removable bearing and circuit breaker housing tting said frame structure for quick removal therefrom for substitution of another as and for the Purposes side channels, a fixed plate and an adjustable plate itting in at least one of said channels, said plates having their engaging surfaces serrated, and said adjustable plate having end-slots whereby the plate may he accurately and permanently positioned on the fixed plate to properly time the rotor field break and the circuit breaker, both plates having cooperating lever slots and a timing lever passing through said slots into engagement with a part of the circuit breaker.

LE ROY S. DUNHAM. ARTHUR F. ROBERTSON. 

